LENS APERTURE
The aperture is the size of the hole (iris) your camera looks through to take your photo.
Varying the aperture size changes the amount of light you let in.
The bigger the aperture, the more light is received by your sensor.
The smaller the aperture the less light is received by your sensor.
A large aperture lens has a “fast” aperture; which is beneficial in low level lighting

BUYING A CAMERA
To understand what camera to buy you really need to know where digital cameras came from.Digital cameras evolved from film cameras. In modern cameras the film has been replaced by a digital sensor.35mm film cameras; known as “full frame cameras“; were mainly what amateurs used, because the small film size had dust problems.This “full frame format” size is now used in many “top of the range” digital cameras.

A “full frame camera” records an image of 2.4 x 3.6cm.
This isn’t very big, and with film cameras was prone to all sorts of problems with dust and scratches. Actually these supposedly “top of the range” full frame cameras are known as “small format” cameras. This is because in the days of film cameras Professionals tended to use larger format film cameras like Hasselblads, Mamiyas and Bronicas
which had an image format of 6 x 6 cm or 6 x 4.5 cm, or sometimes 6 x 7, or 6 x 9 cm.
This larger format minimised problems with dust, scratches and film grain. These cameras are known as “medium format cameras“.

Top of the range Canon & Nikon, etc digital cameras are usually “small format”, with a “full frame” sensor. A full frame digital sensor is much smaller than the “medium format” digital sensor used in cameras like Phase Ones & Hasselblads.

The quality of a medium format digital camera; like a Hasselblad; makes a digital full frame (small format) camera look stupid (at a cost). However most people don’t need that high quality, so medium format digital cameras; like Hasselblads and Phase One’s are more often used in fashion and advertising photography.

WHAT IS A DSLR ?
Most recent small and medium format film cameras were SLRs. SLR stands for single lens reflex.
This means you look through the lens that actually takes the photo via a mirror system.
Hence the digital equivalent is known as a DSLR . i.e. a Digital SLR.

Today’s full frame digital cameras have in many ways taken the market position of the old medium format film cameras.
These full frame cameras are usually DSLR s. A DSLR is a digital version of the old SLR film cameras.
DSLRs usually have interchangeable lenses. You look through an optical viewfinder via a mirror.
The mirror flips out of the way when you take the photo.

There are smaller format DSLRs than full frame format DSLRs, known as APSC format cameras.
A smaller format means a smaller digital sensor.

WHAT IS THE DIFFERENCE BETWEEN jpeg and RAW ?
jpeg is a form of compression of the data from your camera sensor. Professional cameras maintain the RAW (uncompressed) data.
If your camera only shoots jpegs then the RAW data is being thrown away. If you don’t shoot RAW then you are loosing your options of improving the image later.
But if you can’t be bothered with image mainipulation, photoshop, etc., then maybe jpeg compression is fine for you ?

INTERCHANGEABLE LENSES can give you a lot of flexibility in your photography.
Every time you change a lens it’s a good idea to point the camera body downwards to stop dust falling into it.
Many interchangeable lens camera have automatic sensor cleaners that are supposed to help vibrate dust off the sensor.

COMPACT CAMERAS are usually APSC format or smaller; and without a moving mirror.

SHOULD I BUY A DSLR OR A MIRRORLESS CAMERA ?Things are rapidly changing. Designers are either trying to make the camera mirror translucent (and static), or do away with it altogether.
Translucent mirrors only let part of the light go to the sensor.
Abandoning a camera mirror altogether means you have to view your subject on a screen rather than through the mirror system.
That’s all very well, but these screens can be difficult to see in daylight, and may lag in their performance.
So now digital viewfinder (not traditional optical viewfinders) are being introduced by some manufacturers.

What to buy ? Its YOUR decision, NOT the online pundit’s, or the camera shop man’s, decision.

The old rules rules still apply Dust is the photographers enemy. The smaller the camera sensor, the more dust affects it. The smaller the camera sensor the more difficult it is to clean. The smaller the camera sensor, the less its image quality. The smaller the camera sensor the more prone it is to “noise”.

DSLRs aren’t usually waterproof. (some models are “water resistant”)
If you use them in the rain you need waterproof covers and/or higher spec equipment.
Remember if you let water in you trash your gear.

Want to use your DSLR camera underwater ? You need a very expensive waterproof housing . They are a pain to use.
Maybe a cheaper waterproof camera would be better ?

Want something really compact ? This is where it gets really complicated.
To compete with the mirrorless compact cameras there are now compact versions of APSC format DSLR’s.

Want to shoot RAW and not just jpeg ? Many compacts and waterproof cameras can’t shoot RAW.

Want interchangeable lenses? That used to rule out compact digital cameras – but now it doesn’t.

SHOULD MY CAMERA SHOOT VIDEO ?
Want a DSLR camera that shoots video ? You really need to hang a lot of bits on a DSLR to make it work really well as a video camera.
By the time you set it up professionally, you would probably be better off with a video camera (camcorder) instead.
In any case video compression will throw away a lot of the quality.
But then again maybe you want one as a dual purpose lighter , (maybe cheaper ) camera?
Professional video makers often use DSLRs to get very shallow depth of field – probably the last thing an amateur wants.

Want to take several lenses on a photography trek ?
Many of the best zoom lenses weigh a ton, compared with non zoom (prime) lenses.
If you don’t want a bad back you would probably be better off with prime lenses.
Oh, yeah; by the way; prime lenses usually give higher quality results than zoom lenses. (Unless you buy low quality “bottletops”) – see our Jargon Buster Page

Photography Tips 4. You drop your lens. It’s going to smash – but only if you let it.

One of the photography tips you probably won’t have thought of.
Professionals know a secret about how to minimise damage to a dropped lens.
Try and catch it with your foot as it falls. This should minimise the damage.

Practice with a tennis ball. It’s a little known photography technique.

WARNING don’t try this with something so heavy it could injure your foot; or where you could overbalance and injure yourself.

So the camera salesman persuaded you to buy a UV filter; or even a skylight filter; with your new digital camera lens.
Why? Because he wanted the sale. (However some lenses may require a filter as a dust seal)

All a UV or a skylight filter does optically is to detract from your image quality by causing any or all of of these:- reflections, flare, image degradation, vignetting. Good lenses are already UV coated, and a skylight filter is a warming filter meant for film cameras.

There are a few caveats to this tip:-

1. Many people put them on “to protect their lenses from scratches” – but why not just be careful instead? Simply using a lens hood may give you all the protection you need; without un-necessary image degradation

2. Some lenses may not be dust or water sealed without a filter screwed in. Check your lens specifications.

Photography Tips 6. Use A Lens Hood

This one of our photography tips is really basic. If you don’t shield your lens from the sun you will get “flare”.
Flare is great big white and coloured splodges all over your image . Flare radiates from the suns position.
Apart from the main flare around the sun (or other light source) you also get shaped patches of flare across your image from the lens aperture.

Another bonus is that a lens hood can help protect your lens from scratches.

Photography Tips 7. Save money on lenses part 2.

Lens apertures are denoted by f numbers. The smaller the f number the larger the lens aperture.
Lenses with very large apertures (small f numbers) let more light into your camera at that aperture setting. That’s good.
Lenses designed to work well at large apertures involve a design compromise; so that they probably don’t work well at smaller apertures (or are heavy). That’s bad.Lenses with large apertures are more expensive than equivalent lenses with slightly smaller apertures. Bad

It’s quite common for a cheaper smaller aperture lens to outperform or equal its more expensive competitor; when they are both used at smaller apertures.

Photography tips 8. Whatever camera you buy today will soon be out of date. Enjoy the camera you buy and live with it – it’s just a tool.

Photography tips Summary.
Unless you really need that fast aperture lens, you can frequently get better results; or equivalent results; from a cheaper smaller aperture lens.
If you are only going to post tiny images on facebook there is no point buying that expensive camera that can produce huge blow ups.
Maybe for you a camera phone is all you need ?
There is no point buying heavy gear if it’s so heavy you will never use it.
If you want to use software to process your images then a camera that shoots RAW is a good idea.
If you just want an image straight out of the camera; with no computer processing; then you probably don’t need RAW capability.
If your subject doesn’t move then a more expensive image stabilised lens may be a good idea for low light levels.
An image stabilised lens only minimises camera shake – it is no help whatsoever if your subject moves.
There is no point buying an IS/VR (image stabilised/vibration reduction) lens if you use fast shutter speeds to freeze a moving subject.
The more things that a “super lens” can do the less likely it is going to be as good as a lens that “does less” .
i.e. “Large range zoom lenses” and “fast aperture lenses” are usually a design compromise.
Expensive cameras have expensive repair bills. Damaged cheap cameras can be thrown away and replaced at low cost.